Process for treating hydrocarbon oils



R. T. POLLOCK Original Filed' May 12. 1920 PROCESS FOR TREATING HYDROCARBON OILS wunkuazou muk Aug.

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Patented Aug. 18, 1925.

UNITED STATES PATENT OFFICE.

ROBERT T. POLLOCK, .012 BOSTON, MASSACHUSETTS, ASSIGNOR TO UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA.

PROCESS FOR TREATING HYDBOCARBON OILS.

Original application filed May 12, 1920, Serial No. 380,745. .Divided and this application filed January 26, 1925.

To all whom it may concern;-

Be itknown that I, ROBERT T, PoLL0o a citizen of the. United States, residing in the city of Boston, county of Sufl'olk, and State of Massachus'etts, have invented certain new and useful Im rovements in Processes for Treating Hy rocarbon Oils, 0% which the following is a specification.

This invention relates 'to improvements in a process for. treating hydrocarbon oils and is a division of my co-pending application Ser. No. 380,745, filed May '12, 1920. The invention refers more articularly to a process for converting big into low boiling point hydrocarbons such as gasoline and the like. i v Among its salient objects are to provide a process in which the raw oil'prior to being introduced to the cracking zone is pie-heated by being passed through circulating chambers in the dephlegmator thereby relievin the vapors of their heavy oil content and avoiding the objectional feature of mixing the raw oil with the oil vapors which necessarily extracts a part -of the low boiling point cuts to provide a process by means of which a higher percentage of the low. boiling point distillates may be recovered and a. process which permits" of a subse uent combining of the raw oil andz higher oiling point reflux to be charged to the cracking zone; and in general to providea process of the character referred to.

In the drawings: Figure 1 is a diagrammatic elevational view of the apparatus, i

Figure 2 is a sectional view through a portion of the dephlegmator..

Referring to the drawings, the raw oil is charged to the apparatus from any convenient source by pump 1 through the inlet pipe 2 to the circulating chambers 3,4 and 5 mounted in the dephlegmator 6 which take the form of ducts or hollow partition walls. and furnish a means for interchanging the heat of the generated oil vapors to the raw oil and at the same time act as a cooling or condensing agent to said vapor. 'The raw oil circulates first through the chamber 3, thence through the ipe 7 to the chamber 4 and finally through t e pipe 8 to the chamber 5 from which it is d'rawnofi through the line 9 and charged to the heating zone.-

7 Serial No. 4,641.

A valve 10 is interposed in the line 2 and a similar valve 11 in the draw-ofi line 9.

The reflux recovered from the dephlegmator is drawn off through the pipe 12 which is controlled by a valve 13 and is then combined with the raw oil. which has been preheated in 'the dephlegmator. The mixture is then charged to the heating zone. The proportions of raw oil and reflux in this mixture may be controlled by the valves 13 and 11. The raw oil with its reflux content is introduced through the inletline -1 1: to the heating tubes 15 which are mounted above a furnace 16 which is preferably heated by means of gas burners 17. The heated oil passes from the heating tubes through the connecting pipe 18 to the vapor chamber 19 where the greater part of the cracking takes place. The vapors released in this chamber rise into the line 20 by means of which they are directed to the lower part of the dephlegmator 6. In the dephlegmator the vapors pass through the risers 21 through the separate stages being subjected to the cooling and condensing ef-' fect of the raw oil. Stand ipes 22 control the depth of the pools oi reflux which are maintained in separate stages. The reflux overflowing fromthese stages is drawnv off through the line 12 as explained. The uncondensed vapors pass out through the top. of the dephlegmator through the gooseneck 23 and, are condensed in the coil 24 mounted in the water condenser 25. From the water condenser the distillate is drawn off through line.26 and collected in a suit able receiver in the tail house, not shown. Valves 27, 28 and 29 interposed inthe lines 20, 23 and 26 respectively, furnish means 7 f or regulating the flow of vaporsand liquids in the lines and at the same time a means for controlling the pressures in the different portions of the still.

The operation of the process is as follows: the raw oil is introduced and circulated through the hollow partition walls of the dephlegmator where it is preheated and condenses the higher 'boiling point fractions of the oil from the oil vapors. This preheated raw oil is then combined with the refiux' from the dephlegmator and the mixture charged to'the heating tubes where it is raised toa cracking temperature. The'oil vapors which are released during the cracking of the oil pass up through the dephIe'gQ mator where the higher boiling point fractions are condensed therefrom and are drawn ofi' as reflux. The lower boiling point or lighter fractions pass over to be condensed and collected as distillate in the receiver. changing of a portion of the heat contained in the oil vapors to the raw oil which causes a condensing out of the higher boiling point oil fractions, without the objectionable feature of having the raw oil intimately intermingled with the oil vapors during dephlegmation. Where the raw oil comes into intimate contact with the heated oil vapors-there is. a consequential absorbing of a certain amount of the lighter fractions by the raw oil and therefore a decreased efliciency in the process.

An illustrative run of midcontinent gas oil is as follows: Gas oil of approximately 31 or 32 B. is preheated as explained in the dephlegmator and combined with the reflux therefrom. This mixture is charged to the cracking tubes where it is subjected to a heat of about 800 F. The heated oil is then directed to the vapor chamber where it is maintained at a heat of about 700 to 750 F. and the vapors released therefrom. After being dephlegmated in a dephlegmator of this type, a yield of from 50 to pressure distillate having an end point of about 450 F. is obtained.

I claim as my invention:

1. A process for. the conversion of hydrocarbon oils, consisting in subjecting a stream of oil while passing through a heating-tube to a cracking temperature, in delivering the highly heated oil to an enlarged chamber, in discharging vapors generated from the heated oil to a dephlegmator, in introducing a'stream of oil to the dephlegmator to pass therethrou h in indirect heat conductive relation with the vapors traveling through said dephlegmator without permitting physical intermingling of such stream of oil with said vapors to assist in condensing the insufliciently cracked vapors, in preventing the return of unvaporized residue from the enlarged chamber to the heating tube, in introducing preheated oil from the dephlegmator and reflux condensate to the inlet side of the heating tube, and in maintaining a By this process I have an inter phle vapors generated from the oil to a dephlegmator, in introducing charging-oil to the dephlegmator to pass therethrough while in indirect heat conductive relation with the vapors to be maintained out. of physical contact with the vapors. and to assist in condensing the insufliciently cracked vapors undergoing dephlegmation, in collecting the condensate in pools in the dephlegmator through each of which pools the vapors must percolate and with which condensate said preheated charging oil is not'permitted to physically commingle in the dephlegmator, in preventing the return of unvaporized residue from the enlarged zone to the heating tube, in passing reflux condensate and preheated charging oil from the-dephlegmatorto the inlet side of the heating tube to travel therethrough for treatment, and in maintainin a superatmospheric pressure on the oil -un ergoing conversion.

3. A process for oil conversion, consisting insubjecting a stream of hydrocarbon oil while passing through a heating tube to a cracking temperature, in delivering the highly heated oil to an enlarged chamber where conversion occurs, in discharging vapors generated from the oil to a 'dephleg-' mator, in introducing astream of charging oil to the dephlegmator to pass therethrough while maintained out of physical contact with the vapors traveling through the dephlegmator to assist incondensin the insufficiently cracked vapors, in with rawing in a stream the preheated charging oil from the dephlegmator, in separately withdrawing reflux condensate from the deator unmixed with charging oil, and indirectly introducing to the inlet side of the heatin coil the separately withdrawn char mg 011 and reflux condensate in a comming ed composite streamv to pass there.- through for treatment, and in maintaining a superatmospheric pressure on the oil undergoing conversion.

ROBERT T. POLLOCK.

DlSCLAl MER 1,550,568.R0be1't T. Pollock, Boston, Mass. Pnoonss FOR TREATING HYDROCARBON OILS. Patent dated August 18, 1925. Disclaimer filed January 2, 1934,

by the patentee, the assignee, Universal Oil Products Company, approving and concurring.

Hereby enters this disclaimer to the subject matter constituting claim 1 of the patent, which reads as follows:

A process for the conversion of hydrocarbon oils, consisting in subjecting a stream of oil While passing through a heating tube to a cracking temperature, in delivering the highly heated oil to an enlarged chamber, in discharging vapors generate from the heated oil to a dephlegmator, in introducing a stream of oil to the dephlegmator to pass therethrough in indirect heat conductive relation with the vapors traveling through said dephlegmator Without permitting physical intermingling 0 such stream of oil with said vapors to assist in condensing the insufiiciently cracke vapors, in preventing the return of unvaporized residue from the englarged chamber to the heating tube, in introducing preheated oil from the dephlegmator and reflux condensate to the inlet side of the heating tube, and in maintaining a superatmospheric pressure on the oil undergoing conversion. [Ofiicial Gazette January 23, 1934.] 

